Prior art devices are known for detachably securing decorative grilles (or "muntin structures", as they are sometimes called) to window frames.
For example, U.S. Pat. No. 3,221,462 (Pomeroy), discloses slidable fasteners mounted in passageways cut into the opposite ends of the decorative grille. The slidable fasteners may be retracted into the passageways or extended such that a toe portion of the fastener is extended outwardly into an opening provided in the window casing. When the fasteners are extended the grille is secured in place, when they are retracted the grille may be removed from the window frame.
U.S. Pat. No. 3,254,465 (Brengman et al) teaches a spring mounting clip made of resilient material. The clip has a base section that is generally flat with elongated mounting protrusions to engage the sides of a slot in the end of the grille. There is an arcuate terminal section with the convex surface facing away from the base section so as to contact the window frame when the grille is put into place. The arcuate section is connected to the base section by an intermediate section which permits the arcuate section to resiliently flex toward the base when the grille is inserted into a window.
Canadian Patent 1,160,103 (Giguere) discloses a one-piece plastic molded catch member for mounting a decorative grille. In order to receive the grille, the window must have a sash with at least two opposite sides having the base section so as to contact the window frame when the grille is put into place. The arcuate section is connected to the base section by an intermediate section which permits the arcuate section to resiliently flex toward the base when the grille is inserted into a window.
Canadian Patent 1,160,103 (Giguere) discloses a one-piece plastic molded catch member for mounting a decorative grille. In order to receive the grille, the window must have a sash with at least two opposite sides having inwardly facing shallow grooves. The catch member is retained in the end of the grille by a stem having longitudinally extending radial ribs. Each radial rib is of constant triangular cross-section. The clip has a convex head portion having an arcuate arm which overlies the base of the clip and when is resiliently movable towards the bass. When the grille is placed in the window frame, the convex head portions of the clip at each end of the grille are retained in the shallow grooves in the sash.
Accordingly, the prior art discloses the general concept of detachably securing a grille in a window frame using clips secured at the ends of the grille. The prior art teaches that such clips may have resilient arcuate members which frictionally engage the window frame and which may be secured to the grille by a stem having longitudinally extending ribs or elongated protrusions.